Laser diode operable in 1.3μm or 1.5μm wavelength band with improved efficiency

Abstract

A laser diode includes an active layer of a group III-V compound semiconductor device containing N and As as the group V elements. The active layer has exposed lateral edges wherein the N atoms are substituted by the As atoms at the exposed lateral edges by an annealing process conducted in a AsH 3 atmosphere.

What is claimed is:  
     
       1. A semiconductor device, comprising: 
       at least one group III-V mixed crystal semiconductor layer containing a plurality of group V elements, said mixed crystal semiconductor layer containing As and simultaneously N as said group V elements,  
       said semiconductor layer having exposed surface areas in which N is substituted with As, and said semiconductor layer having an inside part, such that said exposed areas confine said inside part of said semiconductor layer,  
       said exposed areas having a bandgap larger than a bandgap of said inside part.  
     
     
       2. The semiconductor device of  claim 1 , wherein said group III-V mixed crystal semiconductor layer is a InGaNAs layer grown epitaxially on a GaAs substrate. 
     
     
       3. The semiconductor device of  claim 1 , wherein said semiconductor layer is an active layer, and wherein said active layer and a layer adjacent to said active layer are free from Al. 
     
     
       4. A semiconductor device, comprising: 
       at least one group III-V mixed crystal semiconductor layer containing a plurality of group V elements, said semiconductor layer containing As and simultaneously N as said group V elements, surface portions of said semiconductor layer being exposed by an etching process,  
       wherein N is replaced with As in said processed surface portions before a growth of a material layer is made so as to bury said processed surfaces,  
       said surface portions having an increased bandgap as compared with an inside portion of said semiconductor layer, and wherein said surface portions confine said inside portion of said semiconductor layer.  
     
     
       5. The semiconductor device of  claim 4 , wherein said group III-V mixed crystal semiconductor layer is a InGaNAs layer grown epitaxially on a GaAs substrate. 
     
     
       6. The semiconductor device of  claim 4 , wherein said semiconductor layer is an active layer, and wherein said active layer and a layer adjacent to said active layer are free from Al. 
     
     
       7. A semiconductor device for generating light having a wavelength greater than 1.1 μm, said semiconductor device comprising: 
       at least one group III-V mixed crystal semiconductor layer containing a plurality of group V elements, said semiconductor layer containing As and simultaneously N as said group V elements, and said semiconductor layer having a surface portion, and said group III-V mixed crystal semiconductor layer having an inside portion,  
       wherein N is replaced with As in said surface portion before a growth of a material layer is made so as to bury said surface portion, such that said surface portion has an increased bandgap as compared with said inside portion.  
     
     
       8. The semiconductor device of  claim 7 , wherein said mixed crystal semiconductor layer has a composition such that said semiconductor device generates optical telecommunication signals in a 1.3 μm optical transmission band. 
     
     
       9. The semiconductor device of  claim 7 , wherein said mixed crystal semiconductor layer has a composition such that said semiconductor device generates optical telecommunication signals in a 1.5 μm optical transmission band.